Help reviving a Korona 5X7

Hello All,

This little newbie went to market and came home with a Korona 5X7 that needs a bit of help. I need to utilize the full 24" of available focal length, but sometime in its long life this camera lost its primary rail and is now assembled on an extension rail. I don't suppose that there is any chance that the rails from Korona 4X5 are the same size as the rails for a Korona 5X7. This bit of wishful thinking would increase my chances of finding a replacement main rail. I'm busy watching eBay for a parts camera, but if anyone can suggest other sources, I would appreciate it. The camera came with a home-built 4X5 reducing back that looks like it uses aluminum Graphlex components that are severely corroded. In my incompetent effort to clean up the ground glass I have managed to make part of the ground glass appear clear. Is there some simple means of fixing this ground glass?

Thank you for the assistance.

Hi, what is the width of the rail? I have a few extra rails, but don't know what camera they would fit.

Jon

Regarding the ground glass, it may depend on what you used to try to clean it in the first place. If it is something that left a clear residue that fills in the texture, you may be able to get rid of it with a simple solvent and then a proper bath with something gentle such as Dawn dish detergent which has excellent de-greasing properties. After a thorough wash and a good rinse, a final rinse in distilled water followed by an alcohol bath before air drying may do the trick.

Hello,
The width of the rail is 7". The distance between the outside edges of the metal gears is 6 1/4". The rail height is 1.075". The distance from the top of the rail to the metal lined slot is 0.4". The distance between the centerlines of the locating dowels is 4 1/8".

I used one of those fibrous kitchen scouring pads and an old toothbrush to try to remove aluminum corrosion residue from part of the ground glass. Is there a particular solvent that would work best?

Thank you all again.

Quote:

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Originally Posted by NightHeron

Hello,

In my incompetent effort to clean up the ground glass I have managed to make part of the ground glass appear clear. Is there some simple means of fixing this ground glass?


I used one of those fibrous kitchen scouring pads and an old toothbrush to try to remove aluminum corrosion residue from part of the ground glass. Is there a particular solvent that would work best?


Thank you all again.

---

At this point you may want to hunt a new piece of ground glass. Unfortunately, you did your present piece no favors by using the scouring pad on it. Not to mention the all the original issues with it.

Using any abrasive produces near cameras and more importantly optics/ground glass are most always a big "No No".

The next time you clean your ground glass follow Tim's directions and you will be in good shape..

BTW- You should be able to find a piece 4x5 ground glass for not much cash.

Quote:

---

Originally Posted by NightHeron

Hello,
The width of the rail is 7". The distance between the outside edges of the metal gears is 6 1/4". The rail height is 1.075". The distance from the top of the rail to the metal lined slot is 0.4". The distance between the centerlines of the locating dowels is 4 1/8".

I used one of those fibrous kitchen scouring pads and an old toothbrush to try to remove aluminum corrosion residue from part of the ground glass. Is there a particular solvent that would work best?

Thank you all again.

---

mine don't fit:(

Hello Jon,

Thank you very much for checking.

Best Regards,